The work on this project was directed towards the development of a phase I, randomized, placebo-controlled, dose-escalation study of an Ebola DNA plasmid vaccine. The hypothesis is that the vaccine will be safe for human administration and elicit immune responses to Ebola. The proposed protocol design is to enroll subjects who will be randomly assigned to DNA vaccine or PBS control injections. If there are no significant toxicities, dose escalation will be initiated. Studies in small animals and non-human primates have shown that regimens of DNA priming followed by administration of viral vectors have demonstrated enhanced immune responses compared to vaccines using DNA alone. Recombinant, replication-deficient adenovirus expressing Ebola genes will be developed and GMP lots produced to further evaluate this vaccination strategy and advance to clinical trials.